1. Technical Field
The present invention pertains to methods and apparatus encoding long sequences or strings of data in order to simplify data storage, processing and/or transmission. More particularly, the invention relates to encoding techniques for significantly reducing the amount of speech data that must be stored, processed and/or transmitted without loss of information contained in the original data sequence. The has particular utilization in speech recognition and compression systems.
2. Discussion of the Prior Art
U.S. Pat. No. 3,940,565 (Lindenberg) discloses an example of numerous prior art speech recognition systems wherein the speech signal is infinitely clipped and the patterns of zero crossings are utilized to identify speech characteristics in the signal. This technique has also been utilized in speech compression systems to reduce the amount of data required to be transmitted without impairing the quality of the reproduced speech at the receiving end of the transmission medium. An example of such a speech compression system may be found in U.S. Pat. No. 3,684,829 (Patterson). In U.S. Pat. No. 4,382,160 (Gosling et al) there is disclosed another speech compression system wherein the patterns of zero crossings and other waveform events, such as amplitude maximum and minimum peaks, are utilized to enhance intelligibility in the reproduced speech signal.
In utilizing waveform event patterns to encode speech signals, very long sequences of data points are required to achieve accurate recognition of the speech contained in the signal. The interminably long strings of data points make processing and storage quite unwieldy and time-consuming, not to mention that an inordinate storage capacity is required. With this problem at hand, the present invention has been derived to provide a technique for encoding the data necessary to identify speech in a speech signal in a way that reduces the amount of data required to be stored, processed and/or transmitted to accurately perform speech recognition and transmission functions.